Testing is an important aspect of effective system utilization. An organization's successful operations, for example, often rely heavily on its ability to engage in transactions over the Internet and/or other communications networks. Further, modern systems are often quite complex, comprising numerous subsystems and utilizing vast amounts of data. Even ordinary transactions, such as purchases of products in an electronic marketplace, can require the collective operation of various subsystems for the transactions to be successful. Minor coding errors in a subsystem can cause various problems throughout a system, such as poor customer experiences and the failure of transactions to be completed. Moreover, as the complexity of such systems increases, it becomes more difficult to test the systems to ensure that they operate properly.